
(FPCore (x y z t) :precision binary64 (- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))
double code(double x, double y, double z, double t) {
return x - (log(((1.0 - y) + (y * exp(z)))) / t);
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
code = x - (log(((1.0d0 - y) + (y * exp(z)))) / t)
end function
public static double code(double x, double y, double z, double t) {
return x - (Math.log(((1.0 - y) + (y * Math.exp(z)))) / t);
}
def code(x, y, z, t): return x - (math.log(((1.0 - y) + (y * math.exp(z)))) / t)
function code(x, y, z, t) return Float64(x - Float64(log(Float64(Float64(1.0 - y) + Float64(y * exp(z)))) / t)) end
function tmp = code(x, y, z, t) tmp = x - (log(((1.0 - y) + (y * exp(z)))) / t); end
code[x_, y_, z_, t_] := N[(x - N[(N[Log[N[(N[(1.0 - y), $MachinePrecision] + N[(y * N[Exp[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z t) :precision binary64 (- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))
double code(double x, double y, double z, double t) {
return x - (log(((1.0 - y) + (y * exp(z)))) / t);
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
code = x - (log(((1.0d0 - y) + (y * exp(z)))) / t)
end function
public static double code(double x, double y, double z, double t) {
return x - (Math.log(((1.0 - y) + (y * Math.exp(z)))) / t);
}
def code(x, y, z, t): return x - (math.log(((1.0 - y) + (y * math.exp(z)))) / t)
function code(x, y, z, t) return Float64(x - Float64(log(Float64(Float64(1.0 - y) + Float64(y * exp(z)))) / t)) end
function tmp = code(x, y, z, t) tmp = x - (log(((1.0 - y) + (y * exp(z)))) / t); end
code[x_, y_, z_, t_] := N[(x - N[(N[Log[N[(N[(1.0 - y), $MachinePrecision] + N[(y * N[Exp[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}
\end{array}
(FPCore (x y z t) :precision binary64 (- x (/ (log1p (* y (expm1 z))) t)))
double code(double x, double y, double z, double t) {
return x - (log1p((y * expm1(z))) / t);
}
public static double code(double x, double y, double z, double t) {
return x - (Math.log1p((y * Math.expm1(z))) / t);
}
def code(x, y, z, t): return x - (math.log1p((y * math.expm1(z))) / t)
function code(x, y, z, t) return Float64(x - Float64(log1p(Float64(y * expm1(z))) / t)) end
code[x_, y_, z_, t_] := N[(x - N[(N[Log[1 + N[(y * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}
\end{array}
Initial program 63.5%
sub-neg63.5%
associate-+l+79.8%
cancel-sign-sub79.8%
log1p-def85.4%
cancel-sign-sub85.4%
+-commutative85.4%
unsub-neg85.4%
*-rgt-identity85.4%
distribute-lft-out--85.3%
expm1-def98.8%
Simplified98.8%
Final simplification98.8%
(FPCore (x y z t) :precision binary64 (if (<= z -0.108) (+ x (/ -1.0 (+ (* t 0.5) (/ t (* y (+ (exp z) -1.0)))))) (- x (* y (/ (expm1 z) t)))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -0.108) {
tmp = x + (-1.0 / ((t * 0.5) + (t / (y * (exp(z) + -1.0)))));
} else {
tmp = x - (y * (expm1(z) / t));
}
return tmp;
}
public static double code(double x, double y, double z, double t) {
double tmp;
if (z <= -0.108) {
tmp = x + (-1.0 / ((t * 0.5) + (t / (y * (Math.exp(z) + -1.0)))));
} else {
tmp = x - (y * (Math.expm1(z) / t));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -0.108: tmp = x + (-1.0 / ((t * 0.5) + (t / (y * (math.exp(z) + -1.0))))) else: tmp = x - (y * (math.expm1(z) / t)) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -0.108) tmp = Float64(x + Float64(-1.0 / Float64(Float64(t * 0.5) + Float64(t / Float64(y * Float64(exp(z) + -1.0)))))); else tmp = Float64(x - Float64(y * Float64(expm1(z) / t))); end return tmp end
code[x_, y_, z_, t_] := If[LessEqual[z, -0.108], N[(x + N[(-1.0 / N[(N[(t * 0.5), $MachinePrecision] + N[(t / N[(y * N[(N[Exp[z], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(y * N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -0.108:\\
\;\;\;\;x + \frac{-1}{t \cdot 0.5 + \frac{t}{y \cdot \left(e^{z} + -1\right)}}\\
\mathbf{else}:\\
\;\;\;\;x - y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}\\
\end{array}
\end{array}
if z < -0.107999999999999999Initial program 84.3%
sub-neg84.3%
associate-+l+84.3%
cancel-sign-sub84.3%
log1p-def100.0%
cancel-sign-sub100.0%
+-commutative100.0%
unsub-neg100.0%
*-rgt-identity100.0%
distribute-lft-out--100.0%
expm1-def100.0%
Simplified100.0%
clear-num99.9%
associate-/r/99.9%
Applied egg-rr99.9%
associate-*l/100.0%
*-un-lft-identity100.0%
clear-num99.9%
Applied egg-rr99.9%
Taylor expanded in y around 0 92.0%
if -0.107999999999999999 < z Initial program 53.0%
sub-neg53.0%
associate-+l+77.6%
cancel-sign-sub77.6%
log1p-def78.0%
cancel-sign-sub78.0%
+-commutative78.0%
unsub-neg78.0%
*-rgt-identity78.0%
distribute-lft-out--77.9%
expm1-def98.2%
Simplified98.2%
clear-num98.1%
associate-/r/98.1%
Applied egg-rr98.1%
Taylor expanded in y around 0 76.7%
expm1-def89.9%
associate-*r/90.7%
Simplified90.7%
Final simplification91.1%
(FPCore (x y z t) :precision binary64 (if (<= y 8.5e+169) (- x (* y (/ (expm1 z) t))) (+ x (/ (- (* z -0.5) (log (* y z))) t))))
double code(double x, double y, double z, double t) {
double tmp;
if (y <= 8.5e+169) {
tmp = x - (y * (expm1(z) / t));
} else {
tmp = x + (((z * -0.5) - log((y * z))) / t);
}
return tmp;
}
public static double code(double x, double y, double z, double t) {
double tmp;
if (y <= 8.5e+169) {
tmp = x - (y * (Math.expm1(z) / t));
} else {
tmp = x + (((z * -0.5) - Math.log((y * z))) / t);
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if y <= 8.5e+169: tmp = x - (y * (math.expm1(z) / t)) else: tmp = x + (((z * -0.5) - math.log((y * z))) / t) return tmp
function code(x, y, z, t) tmp = 0.0 if (y <= 8.5e+169) tmp = Float64(x - Float64(y * Float64(expm1(z) / t))); else tmp = Float64(x + Float64(Float64(Float64(z * -0.5) - log(Float64(y * z))) / t)); end return tmp end
code[x_, y_, z_, t_] := If[LessEqual[y, 8.5e+169], N[(x - N[(y * N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(N[(N[(z * -0.5), $MachinePrecision] - N[Log[N[(y * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq 8.5 \cdot 10^{+169}:\\
\;\;\;\;x - y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}\\
\mathbf{else}:\\
\;\;\;\;x + \frac{z \cdot -0.5 - \log \left(y \cdot z\right)}{t}\\
\end{array}
\end{array}
if y < 8.5000000000000004e169Initial program 67.2%
sub-neg67.2%
associate-+l+80.9%
cancel-sign-sub80.9%
log1p-def86.7%
cancel-sign-sub86.7%
+-commutative86.7%
unsub-neg86.7%
*-rgt-identity86.7%
distribute-lft-out--86.7%
expm1-def98.7%
Simplified98.7%
clear-num98.7%
associate-/r/98.7%
Applied egg-rr98.7%
Taylor expanded in y around 0 80.4%
expm1-def90.0%
associate-*r/90.6%
Simplified90.6%
if 8.5000000000000004e169 < y Initial program 4.2%
sub-neg4.2%
associate-+l+63.2%
cancel-sign-sub63.2%
log1p-def63.2%
cancel-sign-sub63.2%
+-commutative63.2%
unsub-neg63.2%
*-rgt-identity63.2%
distribute-lft-out--63.1%
expm1-def99.7%
Simplified99.7%
clear-num99.6%
associate-/r/99.7%
Applied egg-rr99.7%
Taylor expanded in y around inf 4.2%
mul-1-neg4.2%
distribute-frac-neg4.2%
log-rec4.2%
remove-double-neg4.2%
expm1-def93.0%
Simplified93.0%
Taylor expanded in z around 0 93.0%
Taylor expanded in t around -inf 93.2%
associate-*r/93.2%
mul-1-neg93.2%
neg-mul-193.2%
neg-mul-193.2%
associate-+r+93.2%
distribute-neg-out93.2%
log-prod93.2%
*-commutative93.2%
Simplified93.2%
Final simplification90.7%
(FPCore (x y z t) :precision binary64 (- x (* y (/ (expm1 z) t))))
double code(double x, double y, double z, double t) {
return x - (y * (expm1(z) / t));
}
public static double code(double x, double y, double z, double t) {
return x - (y * (Math.expm1(z) / t));
}
def code(x, y, z, t): return x - (y * (math.expm1(z) / t))
function code(x, y, z, t) return Float64(x - Float64(y * Float64(expm1(z) / t))) end
code[x_, y_, z_, t_] := N[(x - N[(y * N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x - y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}
\end{array}
Initial program 63.5%
sub-neg63.5%
associate-+l+79.8%
cancel-sign-sub79.8%
log1p-def85.4%
cancel-sign-sub85.4%
+-commutative85.4%
unsub-neg85.4%
*-rgt-identity85.4%
distribute-lft-out--85.3%
expm1-def98.8%
Simplified98.8%
clear-num98.7%
associate-/r/98.7%
Applied egg-rr98.7%
Taylor expanded in y around 0 79.3%
expm1-def88.0%
associate-*r/88.5%
Simplified88.5%
Final simplification88.5%
(FPCore (x y z t) :precision binary64 (if (<= z -2.6) x (- x (* z (/ y t)))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -2.6) {
tmp = x;
} else {
tmp = x - (z * (y / t));
}
return tmp;
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
real(8) :: tmp
if (z <= (-2.6d0)) then
tmp = x
else
tmp = x - (z * (y / t))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t) {
double tmp;
if (z <= -2.6) {
tmp = x;
} else {
tmp = x - (z * (y / t));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -2.6: tmp = x else: tmp = x - (z * (y / t)) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -2.6) tmp = x; else tmp = Float64(x - Float64(z * Float64(y / t))); end return tmp end
function tmp_2 = code(x, y, z, t) tmp = 0.0; if (z <= -2.6) tmp = x; else tmp = x - (z * (y / t)); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := If[LessEqual[z, -2.6], x, N[(x - N[(z * N[(y / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -2.6:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x - z \cdot \frac{y}{t}\\
\end{array}
\end{array}
if z < -2.60000000000000009Initial program 84.3%
sub-neg84.3%
associate-+l+84.3%
cancel-sign-sub84.3%
log1p-def100.0%
cancel-sign-sub100.0%
+-commutative100.0%
unsub-neg100.0%
*-rgt-identity100.0%
distribute-lft-out--100.0%
expm1-def100.0%
Simplified100.0%
Taylor expanded in x around inf 75.6%
if -2.60000000000000009 < z Initial program 53.0%
sub-neg53.0%
associate-+l+77.6%
cancel-sign-sub77.6%
log1p-def78.0%
cancel-sign-sub78.0%
+-commutative78.0%
unsub-neg78.0%
*-rgt-identity78.0%
distribute-lft-out--77.9%
expm1-def98.2%
Simplified98.2%
Taylor expanded in z around 0 89.7%
associate-/l*90.5%
associate-/r/87.4%
Simplified87.4%
Final simplification83.4%
(FPCore (x y z t) :precision binary64 (if (<= z -0.62) x (- x (* y (/ z t)))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -0.62) {
tmp = x;
} else {
tmp = x - (y * (z / t));
}
return tmp;
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
real(8) :: tmp
if (z <= (-0.62d0)) then
tmp = x
else
tmp = x - (y * (z / t))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t) {
double tmp;
if (z <= -0.62) {
tmp = x;
} else {
tmp = x - (y * (z / t));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -0.62: tmp = x else: tmp = x - (y * (z / t)) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -0.62) tmp = x; else tmp = Float64(x - Float64(y * Float64(z / t))); end return tmp end
function tmp_2 = code(x, y, z, t) tmp = 0.0; if (z <= -0.62) tmp = x; else tmp = x - (y * (z / t)); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := If[LessEqual[z, -0.62], x, N[(x - N[(y * N[(z / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -0.62:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x - y \cdot \frac{z}{t}\\
\end{array}
\end{array}
if z < -0.619999999999999996Initial program 84.3%
sub-neg84.3%
associate-+l+84.3%
cancel-sign-sub84.3%
log1p-def100.0%
cancel-sign-sub100.0%
+-commutative100.0%
unsub-neg100.0%
*-rgt-identity100.0%
distribute-lft-out--100.0%
expm1-def100.0%
Simplified100.0%
Taylor expanded in x around inf 75.6%
if -0.619999999999999996 < z Initial program 53.0%
sub-neg53.0%
associate-+l+77.6%
cancel-sign-sub77.6%
log1p-def78.0%
cancel-sign-sub78.0%
+-commutative78.0%
unsub-neg78.0%
*-rgt-identity78.0%
distribute-lft-out--77.9%
expm1-def98.2%
Simplified98.2%
Taylor expanded in z around 0 89.7%
associate-/l*90.5%
associate-/r/87.4%
Simplified87.4%
*-commutative87.4%
clear-num87.4%
un-div-inv87.4%
Applied egg-rr87.4%
associate-/r/90.4%
Simplified90.4%
Final simplification85.5%
(FPCore (x y z t) :precision binary64 (if (<= z -0.5) x (- x (/ y (/ t z)))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -0.5) {
tmp = x;
} else {
tmp = x - (y / (t / z));
}
return tmp;
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
real(8) :: tmp
if (z <= (-0.5d0)) then
tmp = x
else
tmp = x - (y / (t / z))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t) {
double tmp;
if (z <= -0.5) {
tmp = x;
} else {
tmp = x - (y / (t / z));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -0.5: tmp = x else: tmp = x - (y / (t / z)) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -0.5) tmp = x; else tmp = Float64(x - Float64(y / Float64(t / z))); end return tmp end
function tmp_2 = code(x, y, z, t) tmp = 0.0; if (z <= -0.5) tmp = x; else tmp = x - (y / (t / z)); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := If[LessEqual[z, -0.5], x, N[(x - N[(y / N[(t / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -0.5:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x - \frac{y}{\frac{t}{z}}\\
\end{array}
\end{array}
if z < -0.5Initial program 84.3%
sub-neg84.3%
associate-+l+84.3%
cancel-sign-sub84.3%
log1p-def100.0%
cancel-sign-sub100.0%
+-commutative100.0%
unsub-neg100.0%
*-rgt-identity100.0%
distribute-lft-out--100.0%
expm1-def100.0%
Simplified100.0%
Taylor expanded in x around inf 75.6%
if -0.5 < z Initial program 53.0%
sub-neg53.0%
associate-+l+77.6%
cancel-sign-sub77.6%
log1p-def78.0%
cancel-sign-sub78.0%
+-commutative78.0%
unsub-neg78.0%
*-rgt-identity78.0%
distribute-lft-out--77.9%
expm1-def98.2%
Simplified98.2%
Taylor expanded in z around 0 89.7%
associate-/l*90.5%
Simplified90.5%
Final simplification85.5%
(FPCore (x y z t) :precision binary64 x)
double code(double x, double y, double z, double t) {
return x;
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
code = x
end function
public static double code(double x, double y, double z, double t) {
return x;
}
def code(x, y, z, t): return x
function code(x, y, z, t) return x end
function tmp = code(x, y, z, t) tmp = x; end
code[x_, y_, z_, t_] := x
\begin{array}{l}
\\
x
\end{array}
Initial program 63.5%
sub-neg63.5%
associate-+l+79.8%
cancel-sign-sub79.8%
log1p-def85.4%
cancel-sign-sub85.4%
+-commutative85.4%
unsub-neg85.4%
*-rgt-identity85.4%
distribute-lft-out--85.3%
expm1-def98.8%
Simplified98.8%
Taylor expanded in x around inf 76.5%
Final simplification76.5%
(FPCore (x y z t)
:precision binary64
(let* ((t_1 (/ (- 0.5) (* y t))))
(if (< z -2.8874623088207947e+119)
(- (- x (/ t_1 (* z z))) (* t_1 (/ (/ 2.0 z) (* z z))))
(- x (/ (log (+ 1.0 (* z y))) t)))))
double code(double x, double y, double z, double t) {
double t_1 = -0.5 / (y * t);
double tmp;
if (z < -2.8874623088207947e+119) {
tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z)));
} else {
tmp = x - (log((1.0 + (z * y))) / t);
}
return tmp;
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
real(8) :: t_1
real(8) :: tmp
t_1 = -0.5d0 / (y * t)
if (z < (-2.8874623088207947d+119)) then
tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0d0 / z) / (z * z)))
else
tmp = x - (log((1.0d0 + (z * y))) / t)
end if
code = tmp
end function
public static double code(double x, double y, double z, double t) {
double t_1 = -0.5 / (y * t);
double tmp;
if (z < -2.8874623088207947e+119) {
tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z)));
} else {
tmp = x - (Math.log((1.0 + (z * y))) / t);
}
return tmp;
}
def code(x, y, z, t): t_1 = -0.5 / (y * t) tmp = 0 if z < -2.8874623088207947e+119: tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z))) else: tmp = x - (math.log((1.0 + (z * y))) / t) return tmp
function code(x, y, z, t) t_1 = Float64(Float64(-0.5) / Float64(y * t)) tmp = 0.0 if (z < -2.8874623088207947e+119) tmp = Float64(Float64(x - Float64(t_1 / Float64(z * z))) - Float64(t_1 * Float64(Float64(2.0 / z) / Float64(z * z)))); else tmp = Float64(x - Float64(log(Float64(1.0 + Float64(z * y))) / t)); end return tmp end
function tmp_2 = code(x, y, z, t) t_1 = -0.5 / (y * t); tmp = 0.0; if (z < -2.8874623088207947e+119) tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z))); else tmp = x - (log((1.0 + (z * y))) / t); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[((-0.5) / N[(y * t), $MachinePrecision]), $MachinePrecision]}, If[Less[z, -2.8874623088207947e+119], N[(N[(x - N[(t$95$1 / N[(z * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(t$95$1 * N[(N[(2.0 / z), $MachinePrecision] / N[(z * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[N[(1.0 + N[(z * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{-0.5}{y \cdot t}\\
\mathbf{if}\;z < -2.8874623088207947 \cdot 10^{+119}:\\
\;\;\;\;\left(x - \frac{t_1}{z \cdot z}\right) - t_1 \cdot \frac{\frac{2}{z}}{z \cdot z}\\
\mathbf{else}:\\
\;\;\;\;x - \frac{\log \left(1 + z \cdot y\right)}{t}\\
\end{array}
\end{array}
herbie shell --seed 2024013
(FPCore (x y z t)
:name "System.Random.MWC.Distributions:truncatedExp from mwc-random-0.13.3.2"
:precision binary64
:herbie-target
(if (< z -2.8874623088207947e+119) (- (- x (/ (/ (- 0.5) (* y t)) (* z z))) (* (/ (- 0.5) (* y t)) (/ (/ 2.0 z) (* z z)))) (- x (/ (log (+ 1.0 (* z y))) t)))
(- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))